Vehicles, such as automobiles, may include airbags designed to inflate and be impacted by occupants during a side impact of the vehicle. For example, a curtain airbag may deploy downwardly from a roof rail alongside windows during a side collision, and the curtain airbag may be impacted by an occupant adjacent to the curtain airbag.
Vehicles may be subject to side impact testing standards for the curtain airbags. As one example, the National Highway Traffic Safety Administration (NHTSA) provides a test procedure designed to simulate a vehicle experiencing a side collision with a pole. The NHTSA procedure provides that a test vehicle holding a test dummy as an occupant collides sideways at 20 miles per hour into a rigid vertical pole 10 inches in diameter. One proposed measure of injury for this test is a brain injury criterion (BrIC). The BrIC is a function of the maximum pitch, roll, and yaw of a head of the test dummy during the test, specifically,
      BrIC    =                                        (                                          ω                xmax                                            66.25                rad                                      )                    2                +                              (                                          ω                ymax                                            56.45                rad                                      )                    2                +                              (                                          ω                zmax                                            42.87                rad                                      )                    2                      ,in which ωxmax is the maximum roll, ωymax is the maximum pitch, and ωzmax is the maximum yaw, all measured in radians per second.